We propose to develop a complete set of sub-chromosomal fluorescence in situ hybridization (FISH) probes for the mouse genome. The probes will be based on both chromosomal microdissection and YAC clones containing large mouse genomic inserts. The microdissection-based probes will be used for spectral banding, a multi-color single chromosome FISH technique to analyze all types of sub-chromosomal rearrangements. Because the spectral banding probe sets (up to 7 probes per chromosome) will be keyed to the standard Giemsa banding pattern, users will be able to describe their findings in terms of conventional G-banding momenclature. A YAC-based set of linkage-cytogenetic FISH probes spaced at about 5 cM intervals, will be developed to coordinate a cytogenetic band-anchored linkage map for the mouse. We also propose to build a set of spectral banding probes for the human karyotype and to use the mouse linkage-cytogenetic probes to coordinate human/mouse co-maps. This interspecies coordination of cytogenetic maps, when used with cross-species FISH, will allow researchers using other mammalian species to have access to the rich human and mouse gene databases, thus widening the commercial market for these probes.